Generally in conventional cars, as is well known, the front and rear bumpers using relief effect of spring or oil pressure are mounted at both the front and rear of a car for absorbing or relieving a shock at the time of collision of the car. However, although the conventional bumpers may be effective in event of a slight collision, they are considerably insufficient for protecting the occupants or the car body in case of a collision during high speed driving. Further, in case that the car is hit from a side or falls or is overturned, since a separate apparatus for relieving or absorbing the shock is not provided in the prior art, not only is the body of a car easily damaged, but also the occupants get hurt and can even be killed by the shock.